Cell morphology is the basis of group morphology, and group morphology is the reflection of cell morphology when groups gather. Bacteria are prokaryotic microorganisms, so the colonies formed are also small; A single bacterium is full of water, so the whole colony is wet and easy to be provoked by the inoculation ring; The cocci form raised colonies; Flagellar bacteria often form colonies with irregular edges; Colonies with capsules have transparent surfaces and smooth edges. The surface of spore colony is dry and wrinkled; Some bacterial colonies that can produce pigments will also show bright colors. When bacterial cells are inoculated into the liquid medium, the liquid medium will become turbid after the bacteria grow. Turbidity varies according to the oxygen demand of bacteria: aerobic bacteria only make the upper culture solution turbid, anaerobic bacteria make the bottom culture solution turbid, and facultative anaerobic bacteria make the culture solution turbid evenly up and down; Some bacteria can form a ring or film on the surface of the culture medium, or produce precipitation at the bottom.